It is known to wrap or bundle packages or other objects by the use of narrow bands of stretch film. Stretch bundling is used to ease handling and to close a container, box or the like. The elasticity of the band or web holds the package closed while additional bands are rotated around the closed package. The effectiveness of stretched plastic film in holding a package together is a function of the force placed upon the package and the strength of the plastic film applied therearound. The use of narrow bands of material to stretch bundle has been limited generally to hand applications. That is, the package to be closed or wrapped is contacted with a stretch film or tape and hand wound over itself around the package. Since hand wrapping is relatively expensive there is needed an automated system with means to enable continuing applications of separate wraps or bands to the same package to be bundled or closed.
There are also known various types of machines for packaging articles but none of them disclose the use of an automatic stretch bundler of the type disclosed in the present invention. In U.S. Pat. No. 4,537,009 (Kreamer) a method and apparatus for packaging articles such as fruit is disclosed. In the Kreamer apparatus two portions of film which are fed between annular film clamping means are used. An outer clamping mechanism of Kreamer firmly clamps the film portions while stretching the film over the article. This type of machine as described by Kreamer utilizes two separate sheets of film to encapsulate fruit in a sealed environment. This machine cannot be used to apply bands of film or tape around an item to be bundled.
The McDowell U.S. Pat. No. 4,545,182 discloses a wrapping system for circular or spiral wrapping by movement of the item during wrapping. McDowell's apparatus comprises a rotating ring which carries a film dispenser adapted to dispense film web or tape spirally around an item to be wrapped. The package 24 of McDowell is placed upon a conveyor means 31 which moves the package 24 downstream as it is wrapped. The conveyor delivers the package 24 into a wrap area 40 atop wrapping conveyor 32 around which rotates film dispensing apparatus 42. The film dispensing apparatus 42 of McDowell comprises a ring-shaped film support member 44 rotably mounted and supported by rollers 52. As conveyor 32 moves package 24 it is spirally wrapped and transported downstream where it is removed after wrapping. Other wrapping systems such as spiral wrapping are disclosed in the July 1985 issue of Material Handling Engineering. Basically, these spiral wrapping machines wrap the article by use of a stretch tape which is rotated around the article in a spiral fashion until substantially the entire outer surface of the article is wrapped. In the Material Handling Engineering article, an overhead spiral wrap machine sometimes called a rotary tower wrapper is disclosed. This type wrapper pays out pre-stretched 20-30 inch wide film around the load or article as the load sits on a conveyor or towline cart.
In U.S. Pat. Nos. 4,549,388 and 4,676,048 (Lancaster) an orbital wrapper with friction drive is disclosed. Lancaster teaches that "after each load is wrapped in a continuous spiral mode, the conveyor assembly is stopped and the spiral film web located between the loads is guided by guide members of the sealing and cutting mechanism into a small sealing area where the film web is clamped together, sonically sealed and severed". The Lancaster system does not wrap the load several times around the same peripheral portion of the load such as in a bundling operation.
In U.S. Pat. No. 4,674,269 (Denda) a wrapping machine is disclosed wherein a stretchable film means is used together with means to lift an article or load to be wrapped. The article lifting means is adapted to raise an article to be wrapped into taut engagement with the film extended at a predetermined position. This type machine is quite complex and expensive and does not use strips or tapes of stretchable film but rather large folds or sheets of stretchable material.
U.S. Pat. No. 4,723,393 (Silbernagel) discloses a process and apparatus for an orbital stretch wrapper to form two layers of opposite pitch on items or bundles. The Silbernagel patent teaches the use of a first and second wrap roll for spiral wrapping of a load. The rolls are placed successively along the length of a conveyor belt separated by at least one width of film. the Silbernagel patent does not teach the application of a plurality of single bands of stretch film or tape around a load in a single location to thereby bundle the load.